Expansion valve



Dec. 10, 1940. s. CALIN! 5 mmuszou VALVE Filled March 16', 1940 9 Fig. 2 8

' 15 liptic spring, one of which ends re Patented Dec.. 10,

UNITED STATES EXPANSION VALVE Gino 'Calini, Turin, Italy Application March 16, 1940, Serial No. 324,408

m ItalyAprll 1, 1939 l 3 Claims.

I Refrigerating machines are generally provided with expansion valves, the regular operation of which is of great importance for a satisfactory refrigerating process. These valves do 'not havea great resistance and in view of their high sensitiveness passive resistances should be avoided and their arrangement should be such as to prevent jamming.

This invention has for its object on expansion valve intended, more particularly but not exclusively for use with refrigerating machines, said valve being of very simple construction and free of any friction. The valve comprises a conical point needle pressed on its seat by a half-e1- on a. fixed point of the valve body and the ther on a movable wall which is exposed to the action of an adjustable springand to thediflerence between the outer pressure and the pressure of the P expanded steam. The needle is carried centrally by the halt-elliptic spring without any guiding means or friction. In the closed position the spring axis registers with the-seat axis; in the open position the spring is depressed and the needle axis may be at an angle .with the seat axis on which the conical point rests without however causing any inconvenience.

The annexed drawing shows an embodiment of the invention.

Fig. 1 is an axial section showing the valve in fully opened position.

Fig. 2 shows the valve in the closed position. The valve body I comprises a cylindrical expansion chamber, in the wall of which are formed 5 two diametrically opposed passages,- the passage '2 serving for the admission of the high pressure fluid and the'passage 3 for delivery of the low I P u -vapour. The passage 2 is threaded for engagement with a' calibrated nozzle I0, on'the 4o outlet of which is fitted the conical point needle II as it will be hereafter described. A tubular filter 2b secured by a nipple 2a is fitted on the passage 2.

The chamber la is closed at its upper end by a 5cover 4 and houses thebellows i; on the cover side the pressure is practically equal to the atmospheric pressure while the pressure of the expanded vapour acts on the bottom or in the chamber. la. The bellows bottom 6 is exposed 50 on its. outer side to the action of the calibrated spring I, which is adjustable by means of a screw 3 threaded in a nipple la on the cover 4, said nipple being closed and protected by a cap a with the interposition of a suitable packing. A-halfdllptic spring I! is compressed between the movable wall Got the bellows and the bottom of the chamber; arms I! serving to secure the springto the valve by means of the nozzle II.- The root of the said spring is provided with two needle H is adjustably. connected to the spring l3 in such mannerthat when the valve is closed (Fig. 2) its axis registers'with the axis of the nozzle I0 and when the valve is open the needle axis is at an angle to the nozzle axis. When the pressure in the chamber la rises above a certain value, which can be determined by adjustment of the spring '|,.the bellows 5 are pressed against the action of the spring I and the half elliptic spring I3 is flattened, the valve needle moves into its seat thus closing the valve (Fig. 2) 5 When on the-contrary, in normal conditions, the pressure in the chamber is maintained under a determined pressure, the movable wall 6 expands downwards thus bending more sharply the halfelliptic spring.

The valve needle is thus removed from its seat and its axis is slightly inclined towards the nozzle axis; the needle point remaininghowever on the nozzle (Fig. 1 The valve is thus opened. a

The half-elliptic spring and its arms work in the manner of apentagonal linkage; the absence of joints and guiding means permit to obtain a sensitive valve of simple construction without any risk of jamming. t

Obviously some constructional details such as the form of the valve body and inner partition may be modified according to requirements without departing from the spirit of the invention.

What I claim is: I

1. Expansion valve comprising a. casing having a movable wall exposed on one side to the outer pressure and on the other side to the pressure in said casing, a half-elliptic spring in said casl ing bearing at one of its ends on'a fixed wall and at its other end on said movable wall and a needle valve carried by said half-elliptic; spring and coating with the admission opening of said, casing. a

, 2. Expansion valve comprising a casing having 40 an admission and a delivery opening, bellows in said casing communicating with the outside, a half-elliptic spring in said casing bearing at one end on a fixed wall of the casing and at its other end on the movable bottom of the bellows, a; 4.5 spring in said bellows adjustable from the o utside,

a needle valve adjustably secured to the central part of the half-elliptic spring and coacting with the admission opening and means for controlling said springs from the outside in such manner as so to bring said needleinto the closed position whenv the pressure in the casing reaches a' predetermined value. V

3. Expansion valve. claimed in claim 2, in which the half-elliptic spring is provided at its 5 ends with two crank extensions, by means, of which it is fixed in the casing. r

GINO 

